The present invention relates to a suction gripper.
When, for example, a container that is loaded up to the ceiling has to be unloaded, one is often confronted with a solid wall of packages. In such a case, only the front of the packages is visible. This has the drawback that a package that has to be gripped only offers one contact surface and that there is very little freedom of movement. Since the loading procedure and/or the transportation often causes deformation and/or compression of the packages underneath the package that is going to be gripped, the package that has to be gripped is often in a kind of trough and is held in place by at times considerable clamping forces. Consequently, forces have to be applied to the package in two directions: on the one hand, upward forces to lift it out of the trough and on the other hand, forces perpendicular to the stack of packages in order to pull it out of the stack. The lifting is necessary here since otherwise, the lower package would also move or, in the worst-case scenario, the entire stack of packages would tip over.
When it comes to applying force perpendicular to the package, good results have been achieved so far with suction grippers such as, for example, bellows suction grippers, although these have the disadvantage that they let go in case of lateral forces which, until now, had made it impossible to lift packages by applying suction onto the front surface.